    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *     http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.configuration2.builder.combined;
    018
    019import java.util.Map;
    020
    021import org.apache.commons.configuration2.ConfigurationUtils;
    022import org.apache.commons.configuration2.builder.BasicBuilderParameters;
    023import org.apache.commons.configuration2.builder.BuilderParameters;
    024
    025/**
    026 * <p>
    027 * A specialized parameters object for {@link MultiFileConfigurationBuilder}.
    028 * </p>
    029 * <p>
    030 * A parameters object of this type is used by a configuration builder with
    031 * manages multiple file-based configurations. Such a builder is a bit special
    032 * because it does not create a configuration on its own, but delegates to a
    033 * file-based builder for this purpose. Therefore, parameters inherited from the
    034 * super class are treated differently:
    035 * </p>
    036 * <ul>
    037 * <li>The {@link org.apache.commons.configuration2.interpol.ConfigurationInterpolator
    038 * ConfigurationInterpolator} is needed by a
    039 * {@code MultiFileConfigurationBuilder} to resolve the file pattern. It is
    040 * expected to be set and will not be passed to sub configurations created by
    041 * the builder.</li>
    042 * <li>All other parameters are evaluated when creating sub configurations.
    043 * However, it is preferred to use the
    044 * {@link #setManagedBuilderParameters(BuilderParameters)} method to define all
    045 * properties of sub configurations in a single place. If such a parameters
    046 * object is set, its properties take precedence.</li>
    047 * </ul>
    048 * <p>
    049 * This class is not thread-safe. It is intended that an instance is constructed
    050 * and initialized by a single thread during configuration of a
    051 * {@code ConfigurationBuilder}.
    052 * </p>
    053 *
    054 * @version $Id: MultiFileBuilderParametersImpl.java 1842194 2018-09-27 22:24:23Z ggregory $
    055 * @since 2.0
    056 */
    057public class MultiFileBuilderParametersImpl extends BasicBuilderParameters
    058        implements MultiFileBuilderProperties<MultiFileBuilderParametersImpl>
    059{
    060    /** Constant for the key in the parameters map used by this class. */
    061    private static final String PARAM_KEY = RESERVED_PARAMETER_PREFIX
    062            + MultiFileBuilderParametersImpl.class.getName();
    063
    064    /** The parameters object for managed builders. */
    065    private BuilderParameters managedBuilderParameters;
    066
    067    /** The file pattern. */
    068    private String filePattern;
    069
    070    /**
    071     * Obtains an instance of this class from the given map with parameters. If
    072     * this map does not contain an instance, result is <b>null</b>. This is
    073     * equivalent to {@code fromParameters(params, false)}.
    074     *
    075     * @param params the map with parameters (must not be <b>null</b>)
    076     * @return an instance of this class fetched from the map or <b>null</b>
    077     * @throws NullPointerException if the map with parameters is <b>null</b>
    078     */
    079    public static MultiFileBuilderParametersImpl fromParameters(
    080            final Map<String, Object> params)
    081    {
    082        return fromParameters(params, false);
    083    }
    084
    085    /**
    086     * Obtains an instance of this class from the given map with parameters and
    087     * creates a new object if such an instance cannot be found. This method can
    088     * be used to obtain an instance from a map which has been created using the
    089     * {@code getParameters()} method. If the map does not contain an instance
    090     * under the expected key and the {@code createIfMissing} parameter is
    091     * <b>true</b>, a new instance is created. Otherwise, result is <b>null</b>.
    092     *
    093     * @param params the map with parameters (must not be <b>null</b>)
    094     * @param createIfMissing a flag whether a new instance should be created if
    095     *        necessary
    096     * @return an instance of this class fetched from the map or <b>null</b>
    097     * @throws NullPointerException if the map with parameters is <b>null</b>
    098     */
    099    public static MultiFileBuilderParametersImpl fromParameters(
    100            final Map<String, Object> params, final boolean createIfMissing)
    101    {
    102        MultiFileBuilderParametersImpl instance =
    103                (MultiFileBuilderParametersImpl) params.get(PARAM_KEY);
    104        if (instance == null && createIfMissing)
    105        {
    106            instance = new MultiFileBuilderParametersImpl();
    107        }
    108        return instance;
    109    }
    110
    111    /**
    112     * Returns the pattern for determining file names for managed
    113     * configurations.
    114     *
    115     * @return the file pattern
    116     */
    117    public String getFilePattern()
    118    {
    119        return filePattern;
    120    }
    121
    122    @Override
    123    public MultiFileBuilderParametersImpl setFilePattern(final String p)
    124    {
    125        filePattern = p;
    126        return this;
    127    }
    128
    129    /**
    130     * Returns the parameters object for managed configuration builders.
    131     *
    132     * @return the parameters for sub configurations
    133     */
    134    public BuilderParameters getManagedBuilderParameters()
    135    {
    136        return managedBuilderParameters;
    137    }
    138
    139    @Override
    140    public MultiFileBuilderParametersImpl setManagedBuilderParameters(
    141            final BuilderParameters p)
    142    {
    143        managedBuilderParameters = p;
    144        return this;
    145    }
    146
    147    /**
    148     * {@inheritDoc} This implementation puts a reference to this object under a
    149     * reserved key in the resulting parameters map.
    150     */
    151    @Override
    152    public Map<String, Object> getParameters()
    153    {
    154        final Map<String, Object> params = super.getParameters();
    155        params.put(PARAM_KEY, this);
    156        return params;
    157    }
    158
    159    /**
    160     * {@inheritDoc} This implementation also tries to clone the parameters
    161     * object for managed builders if possible.
    162     */
    163    @Override
    164    public MultiFileBuilderParametersImpl clone()
    165    {
    166        final MultiFileBuilderParametersImpl copy =
    167                (MultiFileBuilderParametersImpl) super.clone();
    168        copy.setManagedBuilderParameters((BuilderParameters) ConfigurationUtils
    169                .cloneIfPossible(getManagedBuilderParameters()));
    170        return copy;
    171    }
    172}